The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 10, 1995
Filed:
Sep. 22, 1992
Wai-Tak P Lee, Fountain Valley, CA (US);
Rockwell International Corporation, Seal Beach, CA (US);
Abstract
The REAL TIME KEYBOARD SCANNER shown herein provides scanning and debouncing, but not multiple key resolution or buffering. At the end of each keyboard scan, the scanner produces a code indicating which key was depressed, or that no key was depressed, or that multiple keys were depressed. If this code is the same as the code in a valid-key register, then no change is made to the valid-key register and no debouncing is performed. If the codes differ, then debouncing is performed. The CPU served by the scanner can examine the code in the valid-key register whenever it finds such examination to be convenient, and need not tie up valuable processing time in continuously monitoring the valid-key register. If desired, an interrupt may be sent to the CPU when the code in the valid-key register is changed.